Diesel Royal Enfield Project in OZ

The thought came to me way back when I was in my teens to place a diesel engine in a motorcycle.  There it stayed until one day I purchased a 4.5 kva diesel generator that was powered by a Yanmar clone L100 engine.  The gen-set was just to good to pull apart, so I looked at purchasing an engine separately, from there it just grew into reality.

This is the gen-set that started it all off, and is still going strong.

Here is the donor bike, it took some searching, but I finally found an Enfield of the right vintage to make it through all the New South Wales RTA (Roads and traffic authority), requirements here in Australia.  The bike is a 1995 500 Bullet, just the bike I needed.


Thought I'd take a few pics before I started pulling the ole girl apart for a new life as a diesel bike. So here we go I said - no turning back now - off came the tank, seat etc, finally stripping the bike down.


The trick was to set the engine up at the right height and close enough to the gearbox to allow the use of the Taurus Chain case etc.  I considered a CVT transmission but once again found it would be a lot easier to keep it simple and run with the original Enfield gearbox.


Next step was to get to work on the front cradle assembly, deciding to do away with chopping the frame to allow enough room for the starter motor.  Any modifications would mean the integrity of the frame would come under scrutiny from the NSW roads and traffic authority.  I was later to find out kick starting the bike is easy enough, also finding the alternator stator is not strong enough to charge a large capacity battery.  This also allows me to use the standard battery saving on weight which is a good move, as its less weight the bike has to pull along.


Everything welded up OK, so now was the time to drill the 4 base holes, checking if everything is straight.  Next step after this was to mark the mounting position on the starter cover mount.


Time to get crackin' on the exhaust system.  For this I purchased two 45 deg bends and one 90 deg bend, along with 1.5 metres of 40mm stainless pipe.  I decided to route the pipe on the LHS to get a neat free flowing exhaust.  After everything bolted up I then finished the head mount.


Happy with the way all the bit's and pieces bolted up, it was then time for a complete pull down and respray, shin n polish to bring the bike back to a presentable condition for the next step - the dreaded engineers certificate, then road worthiness certificate and finally registration.  I've placed some photo's above of the cradle before final mounting into the bike to show the completed unit.


To pass the engineers certificate etc, I had to mount a fuel shut off solenoid close to the fuel pump to shut the engine down.  You'll notice it is not connected in the photo's, this was due to the engine stop switch being faulty and going open circuit which stopped power from getting to the solenoid, and no go.  I later removed this device after registration and rigged up a throttle stop instead.


Other parts used were a Taurus inner chain case, Taurus extended main shaft, Adaptor plate for the space between the engine and inner chain case, 25 tooth duplex front primary chain sprocket specially ordered from Renold chains, solo seat (after market), re-wired electrical system using most of the standard Enfield harness, also using the Boyer regulator that came with the bike.  A lot more little parts went in here n there, but the listed ones are the major parts used.



The bike has been a pleasure to build and to ride.  Always great to have some fun when purchasing fuel for the bike.  The starting date was March 2006, and the bike was registered in October 2006.  This bike may be the first self converted registered diesel motorcycle in Australia. 

Cheers, Andrew :)

Editors Note: Sadly Andrew passed away in 2012. He is greatly missed on the website and forum here at Dieselbike.net

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